Endoscopes have been used in the medical field for many years to look within a selected region of a patient's body, e.g., the colon. The endoscope is typically inserted through an orifice or a surgical incision into a body channel or cavity. Endoscopes are commonly used to perform surgical, therapeutic, diagnostic, or other medical procedures under direct visualization. Conventional endoscopes generally contain several endoscope components, including illuminating means such as light-emitting diodes or fiber optic light guides connected to a proximal source of light, imaging means such as a miniature video camera or a fiber optic image guide, and a working channel. Flexible endoscopes incorporate an elongated flexible shaft and an articulating distal tip to facilitate navigation through the internal curvature of a body cavity or channel. Examples of conventional endoscope designs are described in U.S. Pat. No. 4,706,656, U.S. Pat. No. 4,911,148, and U.S. Pat. No. 5,704,899.
Typical endoscopes provide a conduit for the delivery of an inert gas to insufflate the colon to facilitate examination. The colon, which collapses upon itself when empty, must be inflated to create a space, thereby creating a clear field of view for visualization. In order to insufflate the colon, conventional endoscopic systems utilize an air compressor or other similar gas supply sources. Insufflation creates a space for visualization and keeps the gas pressure constant within the colon by controlling the pressure of the gas supply by means of valves, pressure regulators, and other control devices.
In a standard endoscopic procedure, an operator actively monitors and manually maintains set-point pressure and flow values by checking the displays and operating the controls of the insufflation device. Because many systems do not provide quantitatively accurate methods of regulating the delivery of the gas, those systems can allow variations in the pressure, volume, and flow rate of gas administered during an endoscopic procedure.
In addition, air pressure in the colon is a cause of pain for the patient, both during the procedure and afterwards, due to distension of the bowel if the pressure is not abated. Furthermore, excess insufflation pressure can potentially stress, or even rupture, the colon during the colonoscopy or may cause the development of late perforations if the pressure and volume of the insufflating gas is not accurately controlled and promptly released.